Q.What is meant by a "channel of distribution"?

This is a definitional question, so the answer should state the core idea in one crisp line rather than list examples.

Working: recall the standard definition covered in the meaning/importance section.

A channel of distribution is the route or path, consisting of a set of interdependent organisations and individuals (such as wholesalers, retailers, and agents), through which a product physically moves and changes ownership on its way from the manufacturer to the final consumer. It is also called a trade channel or marketing channel, and its purpose is to close the gaps of place, time, and possession that exist between where and when a product is made and where and when it is actually wanted by the consumer.

Students sometimes define this only as "the way a product is advertised" or "the shop where a product is sold", confusing distribution with promotion or with a single retail point, rather than the full route/network of institutions involved.